mesh in gambit

madhuri

hi iam madhu ,i have a question while doin the mesh.my geometry has three volumes where in the middle pipe has smaller tubes(230) inside a hollow pipe and that is to be rotated.simentaneously the side pipes are fixed and the flow should translate from inlet to outlet.finally my geometry is in the order inlet cylinder,rotating bundle cylinder and outlet cylinder .i dont know how to connect the interfaces of rotating and non rotating and how does the meshing in non-rotating pipe be compatible with the rotating tube bundles.